If a student gets the same word wrong several times, does that count as one error or several errors?

Every time a student reads a word incorrectly, it counts as an error for the purposes of determining her accuracy score. This policy is consistent with several other common reading assessment systems, including DIBELS, AIMSWeb, Fountas & Pinnell BAS, DRA2, and Teachers' College Reading and Writing Project.

There is one exception, which is that if a student misreads a proper noun multiple times, it will still only be counted as one error.